Simple microscopic model for magneto-electric coupling in type-II antiferromagnetic multiferroics

TL;DR

This paper introduces a simple 2D model that captures key features of magneto-electric coupling in type-II multiferroics, explaining phenomena like electric polarization switching and magnetic ordering.

Contribution

The model provides a minimal yet effective framework to understand the origin of multiferroicity in various type-II multiferroic materials.

Findings

Reproduces electric polarization switch-off under magnetic field

Captures dimerized distortion patterns and magnetic ordering

Applicable to multiple material classes like manganites and nickelates

Abstract

We present a simple two-dimensional model in which the lattice degrees of freedom mediate the interactions between magnetic moments and electric dipoles. This model reproduces basic features, such as a sudden electric polarization switch-off when a magnetic field is applied and the ubiquitous dimerized distortion patterns and magnetic $\uparrow \uparrow \downarrow \downarrow$ ordering, observed in several multiferroic materials of different composition. The list includes E-type manganites, RMnO$_3$, nickelates such as in YNiO$_3$ and other materials under strain, such as TbMnO$_3$. In spite of its simplicity, the model presented here captures the essence of the origin of multiferroicity in a large class of type II multiferroics.